Introduction: we measured the hemodynamic changes by the thoracic electrical bioimpedance (TEB) device during induction of anesthesia, endotracheal intubation or insertion of layngeal mask airway (LMA). This TEB device is safe, reliable and estimate continuously and invasively hemodynamic variables. METHODS: We measured the cardiovascular response of endotracheal intubation or that of LMA insertion in thirty ASA class I patients. General anesthesia was induced with injection of fentany 1 microgram/kg, thiopetal sodium 5 mg/kg and vecuronium 1 mg/kg intravenously. Controlled ventilation was for 3 minutes with inhalation of 50% nitrous oxide and 1.5 vol% of enflurane before tracheal intubation or LMA insertion in all patients. The patient was randomly assinged to either tracheal intubation group (ET group) or laryngeal mask airway group (LMA group). Heart rate (HR), mean arterial pressure (MAP), systemic vascular resistance (SVR), stroke index (SI) and cardic index (CI) were measured to pre-induction, pre-intubation, 1 minute after intubation, 2 minute, 3 minute, 5 minute, 7 minute. RESULTS: MAP and SVR were decreased effectively LMA group than ET group during 1 minute after intubation, 2 minute, 3 minute, 5 minute, 7 minute (p<0.05). HR was decreased effectively LMA group than ET group between pre-induction and 1 minute after intubation, between 1 minute after intubation and 2 minute after intubation (p<0.05). But, SI and CI were no difference between ET group and LMA group during induction of anesthesia and intubation (p<0.05). CONCLUSION: The insertion of LMA is beneficial for certain patients than endotracheal tube to avoid harmful cardiovascular response in the management of airway during anesthesia.